From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E24D4C6778C for ; Thu, 5 Jul 2018 07:51:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9712C2401B for ; Thu, 5 Jul 2018 07:51:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="Akp9tPq6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9712C2401B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753294AbeGEHvm (ORCPT ); Thu, 5 Jul 2018 03:51:42 -0400 Received: from mail-oi0-f68.google.com ([209.85.218.68]:41004 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753070AbeGEHvk (ORCPT ); Thu, 5 Jul 2018 03:51:40 -0400 Received: by mail-oi0-f68.google.com with SMTP id k12-v6so15077547oiw.8 for ; Thu, 05 Jul 2018 00:51:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=pyrdzAFIxotjKzkoHqh34v/9FEJT9ksPQdxWc/3HYVc=; b=Akp9tPq62nhjfblwxRvqmwT8NITZMLtvkJ2h3nZXLRl7sa+cdW9sRl3z+y0iQv+V1L RughbG4LmpqbEmmGgv44LVV59hgkVJeI5Gc8WxMu1xa36m8GuZMCrlArvrQ4dtveLD1y +cuz27u3Yv3HQ/U98JoTuAqVySIK/XoP4jAEQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=pyrdzAFIxotjKzkoHqh34v/9FEJT9ksPQdxWc/3HYVc=; b=qiwwvWWFkLq+eXjaa5meH04EV9GvnFFEcen2PKtNK/kdF4+Lw7FdRnMKyNNMpW4Chy CJ+QwfjKThXkR9blo+NgCXe0BMWiCB4JSEFQ1PE07K3tad3W0F1+KEMJ0hAn25/4N4Lh qApUVo/6hZj/vvIT4FGXFEltQLdbnXlTLh+5AbnJr7bTTbRgfigrbBR8i7NeGPI3hrX0 pbpkEh74KYGrz7Zo1gkhOKnRpnky33nio/h7h1AqWwE0W/Ko2NRBprsEli7lCrl2f6Pb QXcI03QFdHImaa2/0bCtdawzdMEJZUOf1cHRG2O5lOy656iB5MZV4xa/l81Ee5/wdzX4 9j1w== X-Gm-Message-State: APt69E1n1cHkHLUS9AlbwX/KmYNLzhsV13UlsC0EqPJmgM3UIsIx3ldD Ft+GgPiVeIhy7HL0B+ff1Z0Kuhhc/NRmYBlU7tVwlw== X-Google-Smtp-Source: AAOMgpcpSGoWQOlonlrfNK6lufv4tP0PtrIwRMx04/nxWLizC7823PFldn4cHUC47gWpEhLe36LMXHtYPBjJd+Df244= X-Received: by 2002:aca:ce0f:: with SMTP id e15-v6mr5831200oig.13.1530777099835; Thu, 05 Jul 2018 00:51:39 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a9d:554d:0:0:0:0:0 with HTTP; Thu, 5 Jul 2018 00:51:19 -0700 (PDT) In-Reply-To: <20180704155123.GO4828@arm.com> References: <1530270944-11351-1-git-send-email-suzuki.poulose@arm.com> <1530270944-11351-25-git-send-email-suzuki.poulose@arm.com> <20180704142241.GG4828@arm.com> <8636wzysfl.wl-marc.zyngier@arm.com> <20180704155123.GO4828@arm.com> From: Peter Maydell Date: Thu, 5 Jul 2018 08:51:19 +0100 Message-ID: Subject: Re: [kvmtool test PATCH 24/24] kvmtool: arm: Add support for creating VM with PA size To: Will Deacon Cc: Marc Zyngier , Christoffer Dall , kvm-devel , Catalin Marinas , Punit Agrawal , lkml - Kernel Mailing List , QEMU Developers , kvmarm@lists.cs.columbia.edu, arm-mail-list Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4 July 2018 at 16:51, Will Deacon wrote: > On Wed, Jul 04, 2018 at 03:41:18PM +0100, Marc Zyngier wrote: >> Not really. Let's say I want my IPA space split in two: memory covers >> the low 47 bit, and I want MMIO spanning the top 47 bit. With your >> scheme, you'd end-up with a 47bit IPA space, while you really want 48 >> bits (MMIO space implemented by userspace isn't registered to the >> kernel). > > That still sounds quite niche for a VM. Does QEMU do that? Not at 47 bits, but we have RAM up to the 256GB mark, and MMIO above that (including a large PCI window), so the general arrangement of having the top end of the IPA space not necessarily be things we've told the kernel about definitely exists. thanks -- PMM From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56777) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1faz3F-0003vH-NY for qemu-devel@nongnu.org; Thu, 05 Jul 2018 03:51:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1faz3E-0008TZ-Qt for qemu-devel@nongnu.org; Thu, 05 Jul 2018 03:51:41 -0400 Received: from mail-oi0-x243.google.com ([2607:f8b0:4003:c06::243]:35148) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1faz3E-0008Ri-KS for qemu-devel@nongnu.org; Thu, 05 Jul 2018 03:51:40 -0400 Received: by mail-oi0-x243.google.com with SMTP id i12-v6so15092750oik.2 for ; Thu, 05 Jul 2018 00:51:40 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20180704155123.GO4828@arm.com> References: <1530270944-11351-1-git-send-email-suzuki.poulose@arm.com> <1530270944-11351-25-git-send-email-suzuki.poulose@arm.com> <20180704142241.GG4828@arm.com> <8636wzysfl.wl-marc.zyngier@arm.com> <20180704155123.GO4828@arm.com> From: Peter Maydell Date: Thu, 5 Jul 2018 08:51:19 +0100 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] [kvmtool test PATCH 24/24] kvmtool: arm: Add support for creating VM with PA size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Will Deacon Cc: Marc Zyngier , Christoffer Dall , kvm-devel , Catalin Marinas , Punit Agrawal , lkml - Kernel Mailing List , QEMU Developers , kvmarm@lists.cs.columbia.edu, arm-mail-list On 4 July 2018 at 16:51, Will Deacon wrote: > On Wed, Jul 04, 2018 at 03:41:18PM +0100, Marc Zyngier wrote: >> Not really. Let's say I want my IPA space split in two: memory covers >> the low 47 bit, and I want MMIO spanning the top 47 bit. With your >> scheme, you'd end-up with a 47bit IPA space, while you really want 48 >> bits (MMIO space implemented by userspace isn't registered to the >> kernel). > > That still sounds quite niche for a VM. Does QEMU do that? Not at 47 bits, but we have RAM up to the 256GB mark, and MMIO above that (including a large PCI window), so the general arrangement of having the top end of the IPA space not necessarily be things we've told the kernel about definitely exists. thanks -- PMM From mboxrd@z Thu Jan 1 00:00:00 1970 From: peter.maydell@linaro.org (Peter Maydell) Date: Thu, 5 Jul 2018 08:51:19 +0100 Subject: [kvmtool test PATCH 24/24] kvmtool: arm: Add support for creating VM with PA size In-Reply-To: <20180704155123.GO4828@arm.com> References: <1530270944-11351-1-git-send-email-suzuki.poulose@arm.com> <1530270944-11351-25-git-send-email-suzuki.poulose@arm.com> <20180704142241.GG4828@arm.com> <8636wzysfl.wl-marc.zyngier@arm.com> <20180704155123.GO4828@arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 4 July 2018 at 16:51, Will Deacon wrote: > On Wed, Jul 04, 2018 at 03:41:18PM +0100, Marc Zyngier wrote: >> Not really. Let's say I want my IPA space split in two: memory covers >> the low 47 bit, and I want MMIO spanning the top 47 bit. With your >> scheme, you'd end-up with a 47bit IPA space, while you really want 48 >> bits (MMIO space implemented by userspace isn't registered to the >> kernel). > > That still sounds quite niche for a VM. Does QEMU do that? Not at 47 bits, but we have RAM up to the 256GB mark, and MMIO above that (including a large PCI window), so the general arrangement of having the top end of the IPA space not necessarily be things we've told the kernel about definitely exists. thanks -- PMM